Supplemental energy for low temperature processes

ABSTRACT

Embodiments of the present disclosure generally relate to semiconductor processing, and specifically to methods and apparatus for surface modification of substrates. In an embodiment, a substrate modification method is provided. The method includes positioning a substrate within a processing chamber; and depositing a material on a portion of the substrate by a deposition process, wherein the deposition process comprises: thermally heating the substrate to a temperature of less than about 500° C.; delivering a first electromagnetic energy from an electromagnetic energy source to the substrate to modify a first region of the substrate, the first region of the substrate being at or near an upper surface of the substrate; and depositing a first material on the first region while delivering the first electromagnetic energy.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/118,142, filed Nov. 25, 2020, which is incorporated herein byreference in its entirety.

BACKGROUND Field

Embodiments of the present disclosure generally relate to semiconductorprocessing, and specifically to methods and apparatus for surfacemodification of substrates.

Description of the Related Art

Various processes, such as advanced epitaxial processes, operate at lowtemperatures where surface modification, defect control, and growingheterojunction films is challenging. State-of-the-art systems alsosuffer from pattern-loading effects which occur due to a difference inpattern densities. As an example, a difference in epitaxial film-growthrates occurs when simultaneously growing films in a region of a higherpattern density and a region of lower pattern density. Consequently, theamount of film growth at specific locations becomes locally sparse ordense depending on the local pattern density of the film, causingsignificant and undesirable non-uniformities in the thickness of thegrown film. Further, 3-nm and 5-nm technology nodes requireacross-the-die uniformities that are difficult to achieve with existingsystems. As device geometries shrink to enable faster integratedcircuits, the thermal budget for deposited films must be reduced inorder to obtain satisfactory processing results, good production yieldand robust device performance.

State-of-the-art systems typically utilize either double-sided heating,where the substrate is heated from both the device-side and thenon-device side, or single-sided heating. Such heating systems, andparticularly for forming very small device features, however do notallow control over the surface chemistry of films (e.g., aiding in theadsorption and/or desorption of precursors) during substrate processing.That is, defect control is virtually impossible while staying withinthermal budgets.

There is a need for new and improved apparatus and methods for surfacemodification at low temperatures that overcome the aforementioneddeficiencies.

SUMMARY

Embodiments of the present disclosure generally relate to semiconductorprocessing, and specifically to methods and apparatus for surfacemodification of substrates.

In an embodiment, a substrate modification method is provided. Themethod includes positioning a substrate within a processing chamber; anddepositing a material on a portion of the substrate by a depositionprocess, wherein the deposition process comprises: thermally heating thesubstrate to a temperature of less than about 500° C.; delivering afirst electromagnetic energy from an electromagnetic energy source tothe substrate to modify a first region of the substrate, the firstregion of the substrate being at or near an upper surface of thesubstrate; and depositing a first material on the first region whiledelivering the first electromagnetic energy.

In another embodiment, a method of processing a substrate is provided.The method includes positioning the substrate within a processingchamber; and depositing a layer on a portion of the substrate. Thedepositing a layer on a portion of the substrate comprises: thermallyheating the substrate to a temperature of less than about 500° C.;delivering a first electromagnetic energy from an electromagnetic energysource to the substrate to modify a first region at or near an uppersurface of the substrate; depositing a first layer on the first regionwhile delivering the first electromagnetic energy; delivering a secondelectromagnetic energy from the electromagnetic energy source to thesubstrate to modify a second region at or near an upper surface of thesubstrate, the second region and the first region being the same ordifferent region; and depositing a second layer on the second regionwhile delivering the first electromagnetic energy.

In another embodiment, an apparatus for modifying a surface of asubstrate is provided. The apparatus includes a substrate processingchamber; a thermal heating source to heat the substrate at a temperatureof less than about 500° C., the thermal heating source configured toheat a backside of the substrate; and an electromagnetic energy sourceto emit electromagnetic energy during a deposition process, theelectromagnetic energy configured to modify a deposition precursor, aregion at or near an upper surface of the substrate, or both, during thedeposition process.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may be applied toother equally effective embodiments.

FIG. 1A illustrates a schematic sectional view of a backside heatingprocessing chamber with a supplemental energy source according to atleast one embodiment of the present disclosure.

FIG. 1B illustrates a schematic side view of the processing chambertaken along line 1B-1B in FIG. 1A according to at least one embodimentof the present disclosure.

FIG. 1C is a cross-section of the energy source of FIGS. 1A and 1B toprovide supplemental energy to the substrate according to at least oneembodiment of the present disclosure.

FIG. 2 is a flowchart showing selected operations of an example methodfor processing a substrate according to at least one embodiment of thepresent disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments of the present disclosure generally relate to semiconductorprocessing, and specifically to methods and apparatus for surfacemodification of substrates. The inventors have found new and improvedmethods and apparatus that enable surface modification of semiconductorsubstrates at, e.g., low temperatures. Briefly, and in some examples, anelectromagnetic energy source, such as a UV lamp array, pulsed lamparray, or a light emitting diode (LED) assembly, is used to control,e.g., the surface chemistry during substrate processing. Theelectromagnetic energy source enables, e.g., reactions to occur on thesubstrate surface without having to heat the wafer at high temperatures.For example, adsorption and desorption of gas molecules can occur atlower temperatures by utilizing the electromagnetic energy source. As aresult, the supplemental energy from the electromagnetic energy sourceenables a broader process window for low-temperature processes (e.g.,below about 550° C., such as about 300° C. to about 450° C.) where thereactions otherwise may not occur. The embodiments described herein canenable better selectivity and control over both forward and reversechemical reactions at the substrate surface, leading to less waferdefects and improved thickness uniformity. Embodiments described hereincan also provide greater control over the fabrication of smallerdevices, leading to increased performance and higher throughput.

3-nm and 5-nm technology nodes require across-the-die uniformities thatare difficult to achieve with existing systems. In these systems, lowthermal budgets are utilized to maintain device performance. However,when the temperature is too low, suitable deposition rates using thermalactivation cannot be achieved. Embodiments described herein solve thisissue by, e.g., adding energetic photons to the surface of the substratewhere deposition is occurring, and allowing higher growth rates and/orthroughputs at a sufficiently low substrate temperature.

Further, modification of the substrate by conventional methods typicallytargets bulk modification. In contrast, embodiments described hereinenable surface modification of the substrate. In some embodiments, thewavelength of radiation emitted by the electromagnetic energy source isselected such that the bulk material from which the substrate is formedis substantially unmodified while the surface of the substrate ismodified.

The following illustrative, but non-limiting, examples are put forth soas to provide those of ordinary skill in the art with a completedisclosure and description of how to make and use embodiments of thepresent disclosure, and are not intended to limit the scope ofembodiments of the present disclosure.

FIG. 1A illustrates a schematic sectional view of a processing chamber100 according to at least one embodiment of the present disclosure. Theprocessing chamber 100 is a backside heating processing chamber. FIG. 1Billustrates a schematic side view of the processing chamber 100 takenalong line 1B-1B in FIG. 1A. It is noted that a liner assembly 163 and acircular shield 167 has been omitted from FIG. 1B for clarity. Theprocessing chamber 100 may be used to process one or more substrates,including the deposition of a material on an upper surface of asubstrate 108. The processing chamber 100 may include an array ofradiant heating lamps 102 for heating, among other components, a backside 104 of a substrate support 106 disposed within the processingchamber 100. In some embodiments, the array of radiant heating lamps maybe disposed over an upper plate 128. The substrate support may be adisk-like substrate support as shown by the substrate support 106 ofFIG. 1A; or the substrate support may be a ring-like substrate support107 with no central opening as shown in FIG. 1B, which supports thesubstrate from the edge of the substrate to facilitate exposure of thesubstrate to the thermal radiation of the lamps 102. In someembodiments, the substrate support 106 may be a multiple arm design

Referring back to FIG. 1A, the substrate support 106 is located withinthe processing chamber 100 between the upper plate 128 and a lower plate114. The upper plate 128, the lower plate 114, and a base ring 136 thatis disposed between the upper plate 128 and the lower plate 114generally define an internal region of the processing chamber 100. Thesubstrate 108 (not to scale) can be brought into the processing chamber100 and positioned onto the substrate support 106 through a loading port103, which is obscured by the substrate support 106 in FIG. 1A but canbe seen in FIG. 1B.

The substrate support 106 is shown in an elevated processing position.However, the substrate support 106 may be vertically traversed by anactuator (not shown) to a loading position below the processing positionto allow lift pins 105 to contact the lower plate 114, pass throughholes in the substrate support 106, and raise the substrate 108 from thesubstrate support 106. A robot (not shown) may then enter the processingchamber 100 to engage and remove the substrate 108 therefrom though theloading port 103. The substrate support 106 then may be actuated up tothe processing position to place the substrate 108, with its device side116 facing up, on a front side 110 of the substrate support 106.

The substrate support 106, while located in the processing position,divides the internal volume of the processing chamber 100 into a processgas region 156 that is above the substrate 108, and a purge gas region158 that is below the substrate support 106. The substrate support 106is rotated during processing by a central shaft 132 to minimize theeffect of thermal and process gas flow spatial anomalies within theprocessing chamber 100 to, e.g., facilitate uniform processing of thesubstrate 108. The substrate support 106 is supported by the centralshaft 132. The central shaft 132 moves the substrate 108 in an up anddown direction 134 during loading and unloading, and in some instances,during processing of the substrate 108. The substrate support 106 may beformed from silicon carbide or graphite coated with silicon carbide to,e.g., absorb radiant energy from the lamps 102 and/or conduct theradiant energy to the substrate 108. In general, the central windowportion of the upper plate 128 and the bottom of the lower plate 114 areformed from an optically transparent material such as quartz.

One or more lamps, such as an array of the lamps 102, can be disposedadjacent to and beneath the lower plate 114 in a specified, desiredmanner around the central shaft 132. The lamps 102 can independentlycontrol the temperature at various regions of the substrate 108 asprocess gas passes over, thereby facilitating the deposition of amaterial onto the upper surface of the substrate 108. While notdiscussed here in detail, the deposited material may include galliumarsenide, gallium nitride, or aluminum gallium nitride.

The lamps 102 may be configured to include bulbs 141 and be configuredto heat the substrate 108 to a temperature within a range of about 200degrees Celsius to about 1600 degrees Celsius. Each lamp 102 is coupledto a power distribution board (not shown) through which power issupplied to each lamp 102. The lamps 102 are positioned within alamphead 145 which may be cooled during or after processing by, forexample, a cooling fluid introduced into channels 149 located betweenthe lamps 102. The lamphead 145 conductively and radiatively cools thelower plate 114 due in part to the close proximity of the lamphead 145to the lower plate 114. The lamphead 145 may also cool the lamp wallsand walls of the reflectors (not shown) around the lamps. Alternatively,the lower plate 114 may be cooled by a convective approach. Dependingupon the application, the lampheads 145 may or may not be in contactwith the lower plate 114. As noted above, and in some embodiments, thelampheads 145 may be positioned over and/or in contact with the upperplate 128. In some examples, the lamps 102 are configured to heatcomponents of the processing chamber 100 to improve cleaning of internalsurfaces of the processing chamber.

A circular shield 167 may be optionally disposed around the substratesupport 106 and surrounded by the liner assembly 163. The circularshield 167 can prevent or minimize leakage of heat/light noise from thelamps 102 to the device side 116 of the substrate 108 while providing apre-heat zone for the process gases. The circular shield 167 may be madefrom CVD SiC, sintered graphite coated with SiC, grown SiC, opaquequartz, coated quartz, or any similar, suitable material that isresistant to chemical breakdown by process and purging gases.

The liner assembly 163 is sized to be nested within or surrounded by aninner circumference of the base ring 136. The liner assembly 163 shieldsthe processing volume (i.e., the process gas region 156 and purge gasregion 158) from metallic walls of the processing chamber 100. Themetallic walls may react with precursors and cause contamination in theprocessing volume. While the liner assembly 163 is shown as a singlebody, the liner assembly 163 may include one or more liners withdifferent configurations.

An optical pyrometer 118 may be used for temperature measurements andtemperature control of the substrate support during backside heating ofthe substrate 108 from the substrate support 106. Temperaturemeasurements by the optical pyrometer 118 may be performed on thesubstrate's device side 116 having an unknown emissivity since heatingthe front side 110 of the substrate support in the processing chamber100 is emissivity independent. As a result, the optical pyrometer 118can only sense radiation from the hot substrate 108 that conducts fromthe substrate support 106, with minimal background radiation from thelamps 102 directly reaching the optical pyrometer 118.

An electromagnetic energy source 122 (e.g., the electromagnetic energysource described herein) is placed outside the upper plate 128 toprovide supplemental energy (e.g., photons) to the substrate. Theelectromagnetic energy source 122 generates radiation which enters theprocessing chamber 100 through one or more machined channels 126connected to a cooling source (not shown). The one or more machinedchannels 126 connect to a passage (not shown) formed on a side of theelectromagnetic energy source 122. The passage is configured to carry aflow of a fluid such as water and may run horizontally along the side ofthe electromagnetic energy source 122 in any desired pattern covering aportion or entire surface of the electromagnetic energy source 122. Thesubstrate 108 is modified by shining light towards substrate 108 whichmay reorder the substrate 108 and/or assist chemical reactionsinvolving, e.g., process gases and the substrate 108. Theelectromagnetic energy source 122 can assist in adsorption and/ordesorption of precursors which would otherwise not be adsorbed and/ordesorbed. For example, a layer such as nitride, silicide, or oxide canbe grown on the substrate 108 and/or the degree of order in thesubstrate can be increased.

In some embodiments, the electromagnetic energy source 122 can deliverenergy to one side of the substrate (e.g., the device side of thesubstrate). In at least one embodiment, the electromagnetic energysource 122 can deliver energy to both sides of the substrate 108.

FIG. 1C is a cross-section of the electromagnetic energy source 122 ofFIGS. 1A-1B according to at least one embodiment. The electromagneticenergy source 122 is utilized to provide supplemental energy to thesubstrate. Chamber components have been removed for clarity. Theelectromagnetic energy source 122 is positioned above substrate 108.Electrical connections 190 are fed through a chamber lid (not shown).The electrical connections 190 deliver power to each lamp, bulb, LED,etc. of the electromagnetic energy source 122. A voltage is supplied tothe electromagnetic energy source 122 which then supplies energy to afront of the substrate 108. It is contemplated that the electromagneticenergy source 122 can be positioned such that it supplies energy to abottom of the substrate 108. It is also contemplated that there can betwo electromagnetic energy sources 122, one positioned above thesubstrate 108 and another positioned below the substrate 108.

Referring back to FIG. 1A, process gas supplied from a process gassupply source 172 is introduced into the process gas region 156 througha process gas inlet 174 formed in the sidewall of the base ring 136. Theprocess gas inlet 174 is configured to direct the process gas in agenerally radially inward direction. During a film formation process,the substrate support 106 may be located in the processing position,which is adjacent to and at about the same elevation as the process gasinlet 174, allowing the process gas to flow along flow path 173 acrossthe upper surface of the substrate 108 in a laminar flow fashion. Theprocess gas exits the process gas region 156 (along flow path 175)through a gas outlet 178 located on the side of the processing chamber100 opposite the process gas inlet 174. Removal of the process gasthrough the gas outlet 178 may be facilitated by a vacuum pump 180coupled thereto. As the process gas inlet 174 and the gas outlet 178 arealigned to each other and disposed approximately at the same elevation,it is believed that such a parallel arrangement, when combing with aflatter upper plate 128 (as will be discussed in detail below), canenable a generally planar, uniform gas flow across the substrate 108.Further radial uniformity may be provided by the rotation of thesubstrate 108 through the substrate support 106.

A controller 192 is coupled to the processing chamber 100 in order tocontrol the components of the processing chamber 100 as describedherein. The controller 192 includes a central processing unit (CPU) 195,a memory 193, and support circuits 194 for the CPU 195. The controller192 may be any suitable type of general-purpose computer processor thatcan be used in an industrial setting for controlling various chambersand sub-processors. The memory 193, or other computer-readable medium,for the CPU 195 may be one or more of any readily available memoryforms, such as random access memory (RAM), read only memory (ROM), afloppy disk, a hard disk, or any other form of digital storage, local orremote. The support circuits 194 may be coupled to the CPU 195 in aneffort to support the processor in a conventional manner. These circuitsmay include cache, power supplies, clock circuits, input/output (I/O)circuitry and subsystems, and the like. In some embodiments, thetechniques disclosed herein for a deposition process as well as acleaning regime may be stored in the memory as a software routine. Thesoftware routine may also be stored and/or executed by a second CPU (notshown) that is remotely located from the hardware being controlled bythe CPU.

According to at least one embodiment, one or more operations of theapparatus and methods described herein can be included as instructionsin a computer-readable medium for execution by the controller unit(e.g., controller 192) or any other processing system.

The electromagnetic energy source (e.g., the electromagnetic energysource 122) is adapted to emit energy at a wavelength or wavelengthrange over the ultraviolet (UV) region, visible region, and/or infraredregion of the electromagnetic spectrum. By emitting electromagneticenergy, the electromagnetic energy source 122 delivers/suppliesenergetic photons to the substrate 108.

The electromagnetic energy source 122 can include lamp(s), bulb(s),light emitting diode(s), and combinations thereof, which emitenergy/light in the UV, visible, and IR regions. Each individual lamp,bulb, or LED can be customized to emit radiation at, e.g., a specificpower and specific wavelength. In addition, the energy distribution andother parameters can be customized for each lamp, bulb, or LED. Theadded energy is sufficient to aid, e.g., adsorption and/or desorption ofprecursors which would otherwise not be adsorbed and/or desorbed, or notsufficiently absorbed and/or desorbed, by thermally heating thesubstrate alone with a given process window. As such, utilization of theenergy source provides a broader process window and allows additionalenergy control over small features.

Depending on the chemistries involved, delivering electromagnetic energyto the surface of the substrate in the presence of gas precursor can,e.g., enhance the rate of chemical reactions by thermal or other means.For example, the light may excite gas phase molecules, adsorbedmolecules, or even electronically excite the substrate to promote achemical reaction on the surface. The wavelength or wavelength range ofenergy emitted can be selected to promote desirable film processes by,for example, choosing a wavelength or wavelength range which is resonantwith a molecular electronic transition in order to enhance a reactionrate. The wavelength or wavelength range can be chosen to enhanceabsorption of the radiation by the substrate, thereby heating thesubstrate more efficiently.

The electromagnetic energy source 122 is adapted to deliver energy at awavelength or wavelength range from about 10 nm to about 1 mm. In someembodiments, the wavelength or wavelength range of UV light emitted fromthe electromagnetic energy source 122 is from about 10 nm to about 400nm, the wavelength or wavelength range of visible light emitted istypically from about 400 nm to about 750 nm, and the wavelength orwavelength range of IR light is typically from about 750 nm to about 1mm.

The electromagnetic energy delivered to the substrate fromelectromagnetic energy source can be a wavelength or a wavelength range.In some embodiments, the electromagnetic energy delivered has awavelength or wavelength range that is from about 10 nm to about 400 nm,such as from about 50 nm to about 350 nm, such as from about 100 nm toabout 300 nm, such as from about 150 nm to about 250 nm, such as fromabout 150 nm to about 200 nm or from about 200 nm to about 250 nm. Insome embodiments, the electromagnetic energy delivered has a wavelengthor wavelength range that is from about 400 nm to about 750 nm, such asfrom about 450 nm to about 700 nm, such as from about 500 nm to about650 nm, such as from about 550 to about 600 nm. In at least oneembodiment, the electromagnetic energy delivered has a wavelength orwavelength range that is from about 750 nm to about 1 mm, such as fromabout 800 nm to about 950 nm, such as from about 850 nm to about 900 nm.Higher or lower wavelengths or wavelength ranges are contemplated.

In some examples, a wavelength or wavelength range of UV light, IRlight, and/or visible light can be used together.

Flash lamps and/or traditional rapid thermal processing (RTP) lamps canbe used as the electromagnetic energy source 122. Flash lamp basedsystems can operate with pulse durations from about 100 microseconds(μs) to about 100 milliseconds (ms) time range, such as from about 250μs to about 75 ms, such as from about 500 μs to about 50 ms, such asfrom about 750 μs to about 25 ms, such as from about 1 ms to about 10ms, though greater or lesser durations are contemplated. Traditional RTPlamp based systems can operate with pulse durations from about 1 andabout 100 seconds, such as from about 10 seconds to about 90 seconds,such as from about 20 seconds to about 80 seconds, such as from about 30seconds to about 70 seconds, such as from about 40 seconds to about 60seconds, such as from about 40 seconds to about 50 seconds or from about50 seconds to about 60 seconds, though greater or lesser durations arecontemplated. Additionally, or alternatively, the flash lamps and/ortraditional RTP lamps can be continuously on during at least a portionof the substrate processing. The power density can be from about 1 W/cm²to about 1 MW/cm², though greater or lesser power densities arecontemplated. Any number of pulses may be applied depending on thedesired processing result. Gaps between pulses can be from about 100 msto about 100 s, such as from about 500 ms to about 50 s, such as fromabout 1 s to about 25 s, though greater or lesser time gaps betweenpulses are contemplated. Suitable lamps include tungsten-halogenincandescent lamps and xenon flash lamps.

The electromagnetic energy source can include one or more LEDs. Pulsedurations can be from about 1 ms to about 1 second (s), such as fromabout 100 ms to about 800 ms, such as from about 200 ms to about 600 ms,though greater or lesser durations are contemplated. Any suitable numberof pulses may be applied depending on the desired processing result.Additionally, or alternatively, the one or more LEDs can be continuouslyon during at least a portion of the substrate processing. Gaps betweenpulses can be from about 100 ms to about 100 s, such as from about 500ms to about 50 s, such as from about 1 s to about 25 s, though greateror lesser time gaps between pulses are contemplated. Any suitable LEDscan be used including those that emit a power density of about 200Watts/cm² or more, such as about 500 Watts/cm² or more, such as about1000 Watts/cm² or more, and/or less than about 1 MW/cm², though greateror lesser power densities are contemplated. In some embodiments, the oneor more LEDs include those emitting blue light or UV light, e.g., lessthan about 500 nm.

Pulse durations can be about 1 ms or less, such as about 1 μs or less,depending on, e.g., the electromagnetic energy source.

In addition to being able to control pulse duration, repetition rate,number of repetitions and intensity, LEDs can enable the optical pulseshape to be varied by simply controlling the voltage applied to thediodes. Pulse shaping can allow the heating rate to be engineered tobalance process efficiency and the stress gradients in deposited filmsand the substrate both during and after the process.

LEDs can also provide benefits when processing substrates outside thetime region ranging from about 1 millisecond to about 1 second. In someembodiments, LEDs may be used to produce pulses under about 1milliseconds down to the time required to initiate illumination, whichmay be less than about 10 microseconds. These LED pulses partiallyoverlap the pulse regime covered by flash lamps.

In some embodiments, energy is delivered to the substrate in acontinuous and/or a pulsed manner. Different amounts of energy atdifferent wavelengths can also be delivered to the substrate. Forexample, a first amount of electromagnetic energy at a first wavelength(or first wavelength range) and a second amount of electromagneticenergy at a second wavelength (or second wavelength range) can bedelivered simultaneously, at different times, overlapping times,cyclically, or combinations thereof. Thus a plurality of electromagneticpulses can be delivered to the surface of the substrate if desired.Additionally, the electromagnetic energy can be selectively delivered tocertain region(s) at or near the substrate surface. For example, a firstwavelength or wavelength range of radiation can be delivered to a firstregion at or near the substrate surface, and a second wavelength orwavelength range of radiation can be delivered to a second region at ornear the substrate surface. The first region can be the same region or adifferent region as the second region. The selectivity of the light fordifferent regions or layers of the substrate enables areal selectivityand/or depth selectivity. Such selectivity is not obtainable utilizingconventional thermal methods alone.

Referring again to FIGS. 1A and 1B, electrical connections (not shown)supply a voltage to the electromagnetic energy source 122, e.g., theelectromagnetic energy source described herein, which then providesenergy to one or more regions of the substrate 108. In some embodiments,and during processing, the optical pyrometer 118 (or a plurality ofoptical pyrometers) sense the temperature of the substrate 108 at avariety of locations on the back and front of the substrate 108 whichcan be used to help determine the voltage delivered to theelectromagnetic energy source 122 dynamically. Additionally, oralternatively, the temperature can be used to determine the voltageapplied to the electromagnetic energy source 122 for subsequent wafers.Optical pyrometer 118 can detect light of a different wavelength thanthe light from the electromagnetic energy source 122 used to provideenergy and chemically modify the substrate 108 resulting in a moreaccurate determination of substrate temperature.

In some embodiments, a removable window can be placed in front of theelectromagnetic energy source 122. Here, the electromagnetic energysource can get very close to the substrate (e.g., about 10 mm or less,such as about 5 mm away from the substrate). The window preventsdeposition of gases or particles on the electromagnetic energy source122. The window can be cleaned periodically.

As described above, high-temperature substrate processing (e.g.,temperatures above about 550° C., or above about 500° C.) can beundesirable for a variety of substrates. However, when the temperatureis too low (e.g., below 550° C., or below 500° C.), deposition ormodification processes cannot occur (or occur at an undesirably reducedrate) because of the low reactivity of the substrate, process gases, orother reactants involved in the process. That is, it may be desirable todeposit a material on a substrate having temperature-sensitive features.Moreover, even if the processes can occur at lower temperatures,suitable deposition rates using thermal activation alone cannot beachieved economically.

For example, low thermal budgets are utilized to maintain deviceperformance of small device features such as 5-nm and 3-nm structures,among other devices. However, modifying one or more surfaces of 5-nm and3-nm structures using conventional 5-nm and 3-nm processes at lowtemperatures either cannot occur or can only occur with substantiallyincreased deposition times. Similarly, a variety of other processes usedto control the surface chemistry of substrate features (e.g., aiding inthe adsorption and/or desorption of precursors) also cannot occur atreasonable rates. There is currently no available technique to solvesuch challenges.

State-of-the-art techniques to modify substrate surfaces do exist, suchas laser annealing. However, these laser annealing processes areutilized only after deposition for post-deposition processing.

Embodiments described herein overcome these and other challenges by,e.g., selectively activating reactants (precursors, substrate surfaces,etc.) using electromagnetic energy. The electromagnetic energy canenable reactions (e.g., depositions, modifications, et cetera) to occurin new process windows. Here, the electromagnetic energy, in the form ofphotons and/or heat, can be used to dissociate precursor materials,activate surface bonds of the substrate, or otherwise prepare reactantsto undergo a reaction where the reactions otherwise may not occur or maynot occur at economically-feasible rates. The electromagnetic energy canbe utilized to chemically modify a precursor material (e.g., adeposition precursor), a region at or near an upper surface of thesubstrate, or both, during a deposition process. Furthermore, incontrast to conventional laser annealing operations that are performedafter deposition of material(s), embodiments described herein canutilize electromagnetic energy during deposition.

FIG. 2 is a flowchart of a method 200 of processing a substrate (e.g.,the substrate 108) according to at least one embodiment of the presentdisclosure. The method 200 is useful to, e.g., modify the surfacechemistry of the substrate during, e.g., a deposition process. In someembodiments, the method 200 is at least a portion of a method forepitaxially growing a film (such as Si, SiGe, oxides, nitrides, amongothers), though the method 200 can be at least a portion of otherdeposition processes of a variety of films such as chemical vapordeposition (CVD), electrochemical deposition (ECD), epitaxialdeposition, heteroepitaxy deposition, atomic layer deposition (ALD),physical vapor deposition (PVD), or combinations thereof. The methodsare not limited by substrate materials or materials deposited. Forexample, the methods can be applied to deposition of one or more Group13-Group 16 elements (e.g., B, Al, Ga, In, Si, Ge, Sn, N, P, As, Sb, O,S, Se, and combinations thereof), one or more transition metals,combinations thereof, among others. Aspects herein provide formodification of surface chemistry (for example, through additional ofenergy to enhance chemical reactions) to facilitate improved filmgrowth, with reduced impact on the thermal budget of the substrate. Theimpact on thermal budget of the substrate is reduced since the substrateis maintained at a relatively reduced temperature, while only thesurface of the substrate is subject to additional thermal energy tofacilitate enhanced thermal reaction.

A substrate is positioned in a processing chamber (e.g., the processingchamber 100) at operation 210. The substrate is heated at a desiredtemperature, e.g., below about 550° C., such as below about 500° C.,such as from about 50° C. to about 250° C. or from about 200° C. toabout 500° C. at operation 220. In at least one embodiment, thesubstrate is heated to a temperature from about 50° C. to about 600° C.,such as from about 150° C. to about 550° C., such as from about 200° C.to about 500° C., such as from about 250° C. to about 500° C., such asfrom about 250° C. to about 500° C., such as from about 300° C. to about500° C., such as from about 350° C. to about 500° C., such as from about375° C. to about 475° C., such as from about 400° C. to about 450° C.

At operation 230, energy and/or light is supplied/delivered to thesurface of the substrate using an example electromagnetic energy source(e.g., the electromagnetic energy source 122), which is part of thesubstrate processing system, described herein. The energy/light modifiesa region at or near an upper surface of the substrate with the deliveredelectromagnetic energy at operation 240. “At or near an upper surface ofthe substrate” refers to a distance from the surface of the substrate toan inner portion of the substrate. In some examples, this distance fromthe surface of the substrate to an inner portion of the substrate isabout 100 nm or less, such as about 90 nm or less, such as about 80 nmor less, such as about 70 nm or less, such as about 60 nm or less, suchas about 50 nm or less, such as about 45 nm or less, such as about 40 nmor less, such as about 35 nm or less, such as about 30 nm or less, suchas about 25 nm or less, such as about 20 nm or less, such as about 15 nmor less, such as about 10 nm or less, such as about 9 nm or less, suchas about 8 nm or less, such as about 7 nm or less, such as about 6 nm orless, such as about 5 nm or less. Other distances are also contemplated.Energies, wavelengths, number of pulses, pulse duration, and intensity,among other parameters, can be selected to sufficiently modify thesubstrate surface. For example, a first electromagnetic energy having awavelength or wavelength range in the UV region of the electromagneticspectrum is emitted from the electromagnetic energy source and deliveredto the substrate. Subsequently, a second electromagnetic energy having awavelength or wavelength range in the IR region of the electromagneticspectrum is emitted from the electromagnetic energy source and deliveredto the substrate.

In some embodiments, an optical detector 196 is used to detect athreshold at which a parameter of the electromagnetic energy source isadjusted and/or caused to emit radiation. Adjusting a parameter can takethe form of changing the wavelength of energy emitted by theelectromagnetic energy source. Such embodiments enable real-timefeedback for substrate processing. As an example, the optical detectorcan be utilized to change from a first electromagnetic energy (or otherfirst parameter) to a second electromagnetic energy (or other secondparameter).

In some embodiments, a controller (e.g., controller 192) is used todetermine or adjust one or more parameters of the electromagnetic energysource based on a temperature reading of the substrate (by, e.g.,optical pyrometer 118) and/or an optical reading (by, e.g., opticaldetector 196). The controller can determine a voltage applied to the oneor more electromagnetic energy sources based on the temperature readingand/or optical reading.

The method can further include selecting a pulse duration and/or pulseintensity sufficient to treat the substrate with at least one pulse oflight/energy from the electromagnetic energy source. The at least onepulse of light includes one or more wavelengths or wavelength ranges.The method can further include depositing a layer (e.g., a Si-containinglayer, a Ge-containing layer, an oxide layer, a nitride layer, atransition metal-containing layer) via atomic layer deposition, epitaxy,chemical vapor deposition, plasma chemical vapor deposition, or othersuitable deposition methods. That is, the methods described herein canbe utilized with a variety of deposition methods. The methods describedherein can be utilized to fabricate 3D LEDs.

The electromagnetic energy source and methods of using theelectromagnetic energy source enable surface modification of substrateswhen, e.g., high-temperature substrate processing is undesirable. As aresult, the energy from the electromagnetic energy source enables abroader process window for low-temperature processes (e.g., below about550° C., such as from about 300° C. to about 450° C.) where substratesurface modification would otherwise not occur.

In the foregoing, reference is made to embodiments of the disclosure.However, it should be understood that the disclosure is not limited tospecific described embodiments. Instead, any combination of thefollowing features and elements, whether related to differentembodiments or not, is contemplated to implement and practice thedisclosure. Furthermore, although embodiments of the disclosure mayachieve advantages over other possible solutions and/or over the priorart, whether or not a particular advantage is achieved by a givenembodiment is not limiting of the disclosure. Thus, the foregoingaspects, features, embodiments, and advantages are merely illustrativeand are not considered elements or limitations of the appended claimsexcept where explicitly recited in a claim(s). Likewise, reference to“the disclosure” shall not be construed as a generalization of anysubject matter disclosed herein and shall not be considered to be anelement or limitation of the appended claims except where explicitlyrecited in a claim(s).

As used herein, the indefinite article “a” or “an” shall mean “at leastone” unless specified to the contrary or the context clearly indicatesotherwise.

For purposes of this present disclosure, and unless otherwise specified,all numerical values within the detailed description and the claimsherein are modified by “about” or “approximately” the indicated value,and consider experimental error and variations that would be expected bya person having ordinary skill in the art. For the sake of brevity, onlycertain ranges are explicitly disclosed herein. However, ranges from anylower limit may be combined with any upper limit to recite a range notexplicitly recited, as well as, ranges from any lower limit may becombined with any other lower limit to recite a range not explicitlyrecited, in the same way, ranges from any upper limit may be combinedwith any other upper limit to recite a range not explicitly recited.Additionally, within a range includes every point or individual valuebetween its end points even though not explicitly recited. Thus, everypoint or individual value may serve as its own lower or upper limitcombined with any other point or individual value or any other lower orupper limit, to recite a range not explicitly recited.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. A substrate modification method, comprising:positioning a substrate within a processing chamber; depositing amaterial on a portion of the substrate by a deposition process, thedeposition process comprising: thermally heating the substrate to atemperature of less than about 500° C.; delivering a firstelectromagnetic energy from an electromagnetic energy source to thesubstrate to modify a first region of the substrate, the first region ofthe substrate being at or near an upper surface of the substrate; anddepositing a first material on the first region while delivering thefirst electromagnetic energy.
 2. The method of claim 1, furthercomprising selecting a first electromagnetic energy that modifies thefirst region of the substrate without substantially modifying a bulk ofthe substrate.
 3. The method of claim 1, wherein the electromagneticenergy source comprises a light emitting diode, an ultraviolet lamp, aninfrared lamp, or combinations thereof.
 4. The method of claim 1,further comprising delivering a second electromagnetic energy from theelectromagnetic energy source to the substrate to chemically modify asecond region at or near the upper surface of the substrate, the firstregion and the second region being the same or different regions.
 5. Themethod of claim 4, wherein the second electromagnetic energy is of ahigher wavelength than the first electromagnetic energy.
 6. The methodof claim 4, wherein the first electromagnetic energy is ultravioletlight and the second electromagnetic energy is infrared light.
 7. Themethod of claim 4, wherein the first electromagnetic energy, the secondelectromagnetic energy, or both, are in the form of temporally shapedpulses.
 8. The method of claim 7, wherein: pulses of the firstelectromagnetic energy, pulses of the second electromagnetic energy, orboth, are varied as a function of time; wherein a duration of each pulseis about 1 second or less; or a combination thereof.
 9. The method ofclaim 7, wherein the deposition process comprises chemical vapordeposition, electrochemical deposition, epitaxial deposition,heteroepitaxy deposition, atomic layer deposition, physical vapordeposition (PVD), or combinations thereof.
 10. The method of claim 1,wherein thermally heating the substrate at a temperature of less thanabout 500° C. alone does not substantially alter the first region of thesubstrate.
 11. The method of claim 1, further comprising selecting apulse duration and pulse intensity sufficient to modify the first regionof the substrate.
 12. A method of processing a substrate, comprising:positioning the substrate within a processing chamber; and depositing alayer on a portion of the substrate, wherein depositing a layercomprises: thermally heating the substrate to a temperature of less thanabout 500° C.; delivering a first electromagnetic energy from anelectromagnetic energy source to the substrate to modify a first regionat or near an upper surface of the substrate; depositing a first layeron the first region while delivering the first electromagnetic energy;delivering a second electromagnetic energy from the electromagneticenergy source to the substrate to modify a second region at or near anupper surface of the substrate, the second region and the first regionbeing the same or different region; and depositing a second layer on thesecond region while delivering the first electromagnetic energy.
 13. Themethod of claim 12, wherein the electromagnetic energy source comprisesa light emitting diode, an ultraviolet lamp, an infrared lamp, orcombinations thereof.
 14. The method of claim 12, wherein the secondelectromagnetic energy is of a higher wavelength than the firstelectromagnetic energy.
 15. The method of claim 12, wherein the firstelectromagnetic energy is ultraviolet light and the secondelectromagnetic energy is infrared light.
 16. The method of claim 12,wherein: the first electromagnetic energy, the second electromagneticenergy, or both, are in the form of temporally shaped pulses; a pulse ofthe first electromagnetic energy, a pulse of the second electromagneticenergy, or both, are varied as a function of time; or a combinationthereof.
 17. The method of claim 16, wherein a duration of each pulse is1 second or less.
 18. An apparatus for modifying a surface of asubstrate, comprising: a substrate processing chamber; a thermal heatingsource to heat the substrate at a temperature of less than about 500°C., the thermal heating source configured to heat a backside of thesubstrate; and an electromagnetic energy source to emit electromagneticenergy during a deposition process, the electromagnetic energyconfigured to modify a deposition precursor, a region at or near anupper surface of the substrate, or both, during the deposition process.19. The apparatus of claim 18, wherein the electromagnetic energy sourcecomprises an ultraviolet lamp, an infrared lamp, a light emitting diode,or combinations thereof.
 20. The apparatus of claim 18, furthercomprising: a pyrometer to sense a temperature of the substrate at whicha first parameter of the electromagnetic energy source is adjusted orcaused to emit radiation; an optical detector to detect a threshold atwhich a second parameter of the electromagnetic energy source isadjusted or caused to emit radiation; and a controller to determine andadjust the first parameter and second parameter of the electromagneticenergy source.